Sound control chamber



Feb. 2, 1932. w C, STENGER 1,843,524

SOUND CONTROL CHAMBER Filed May 5, 1930 Patented Feb. 2, 1932 PATENT FFKWILLEBALD CONRAD STENGER, OF CHICAGO, ILLINOIS SOUND CONTROL CHAMBERApplication led May 5,

rlhis invention relates to the amplication of sound from cone or otherdiaphragme of loud speakers. It is Vsomewhat the common practice inconnection with the cone type of speaker to surround the large end ofthe cone with, or secure this end of the cone to a baffle board whichserves to prevent direct interception and partial neutralization ofsound waves emanating from the opposite sides of the diaphragm. Thepurposes of the present invention are. to provide an improvedarrangement of a loud speaker unit for the purpose of initially keepingseparate the waves originating at opposite sides of a diaphragm,amplifying each set of w ves, bringing the waves together and deliveringthe same from a common sound outlet. The invention is carried out bymeans of oppositely arranged amplifying devices, one within the other.9i" Referring to the drawings Figure l is a front view of the loudspeaker unit.

Fig. 2 is a sectional View taken on the line 2 2 of Figure l.

Fig. 3 is a sectional view similar to that shown in Fig. 2 vbutillustrates a modification.

Fig. 4 is a front View of another modification.

Fig. 5 is a sectional view taken on the line 5-5 of Fig. 4.

This invention may be carried out in connection with any of thecustomary forms of sound reproducing diaphragms, conical, or Y plain.Means are provided for collecting f sound waves from both sides of thevibrating diaphragm and separately conducting the waves by graduallyenlarged air column devices to a common delivery opening. The

waves from one side of the diaphragm are deflected reversely from theiroriginal direction and merge with the waves emanating from the oppositeside of the diaphragm.

Figures l and 3 show angular forms of the amplifying device while Figure4 shows the same general character of amplifier but one which iscircular in outline.

In Figures 1 and 2 the vibratory cone l is centrally located within theamplifier, the ,n periphery of the cone being attached to a board 2which is provided with a center circu- 1930. Serial No. 450,049.

lar opening 3 through which sound waves may pass from the diaphragm ldirectlyvinto the sound amplifying chamber 4 of the tapering air columnstructure formed by the end wall 5, side walls 6 and top and bottomwalls 8. 6B rllhe outer edges of board 2 form a square extending betweenthe top and bottom walls 8. Partition walls 9 extending from the topwall to the bottom wall are connected at their front edges with theboard 2 and flare outwardiy in a rearward direction toward wall 5 butterminate short of the latter. The walls 9 together with the top andbottom walls 8 therefore form a sound wave directing means for the wavesdelivered at the rear side of cone l. These rearwardly directed wavesare reversed in direction and deflected forwardly by impact with therear wall 5.

Such returned waves therefore tra-vel outn wardly into the soundamplifying chamber 4, and merge with the waves originating from theopposite side of the diaphragm.

The means for vibrating diaphragm l are diagrammatically indicated atl0. The entire structure of the amplifying device aside from thediaphragm is preferably rigid and of non-resonant character. The innerwalls and parts thereof, which arev impinged by the sound waves, arecovered with a pliable material ll which may be asbestos, or amembranous substance such as leather and constituting a thin and rathersoft and pliable lining throughout the sound amplifier.

Figure 8 shows a modication of the structure above described, in whichthe setting of the speaker unit l() and diaphragm l is reversed fromthat Shown in F 2.

In this case the waves from the inside of the cone are directed againstthe rear wall 5 and deflected outwardlv therefrom into the soundamplifying chamber' 4, which also receives directly the waves sent outfrom the outer surface of cone l as directed by the walls 12 which withthe walls 2 and 9 like in Figure 2 form an amplifying chamber 1.3.

In Figures 2 and 3 the walls 9 and 12 extend all the way between the topand bottom walls 8 of the outer amplifying device, but in Figures 4 and5 the inner horn-shaped amplifying device 14 which is circular in crosssection is shown supported by brackets 15 extending inwardly from theouter correspondingly formed but reversely set amplifier 17.

Figure 5 also illustrates the use of a plain diaphragm 16. Meansequivalent to the member 10 shown in Figure 2 for vibrating thediaphragm are omitted from Figure 5.

In the operation of any one of the structures illustrated sound Wavesfrom opposite sides of the diaphragm are separately conducted alongsound amplifying chambers, one set of Waves impinging a fixed Wall andbeing deflected thereby into an amplifying means common to both sets ofWaves.

It Will be understood that the sound control chamber herein disclosed,Which has been described according to its operation for the purpose ofsound reproduction, is of equal utility for the purpose of gatheringsound Waves and concentrating them upon a diaphragm when sound isrecorded andtransmitted. The construction may be varied in sizeconsiderably for specific purposes Without sacrifice in utility orintended mode of operation.

p I claim:

1. A loud speaker sound amplifying unit comprising a flaring tubularstructure, the large end of the tubular structure being` open and thesmali end closed by a hired nonrcsonant Wall, a smaller rigid tubularstructure mounted Within the first mentioned tubular structure, adiaphragm mounted across said smaller tubular structure in position sothat sound Waves from one side of the diaphragm are directed toward theend Wall of the larger tubular structure.

2. A sound amplifying unitcomprising a diaphragm and means for Vibratingthe same, a mounting for said diaphragm comprising a flared rigidtubular structure, the diaphragm extending across the small end of saidtubular structure and the large end of said tubular structure beingopen, a rigid Wall spaced opposite the large end of the tubularstructure, and a larger tubular structure extending from said rigid Walland flared outwardly oppositely to the flare of' the smaller tubularstructure.

3. A sound amplifying construction comprising a rigid flared tube, thesmall end of' said tube being closed by a rigid Wall, a smaller rigidoppositely flared tubular structure Within the first mentioned tubularstructure, and a diaphragm extending across the small end of saidsmaller tubular structure.

l. A sound amplifying construction comprising a rigid flared tube, thesmall end of said tube being closed by a rigid Wall, a smaller rigidoppositely flared tubular structure Within the first mentioned tubularstructure, a diaphragm extending across the small end of said smallertubular structure, and a pli-

